PROTECTION CIRCUIT OF VIDEO DISPLAY

摘要

PURPOSE: A protection circuit of the video display is provided to obtain the improved charging efficiency of a capacitor and the increased speed for interrupting beam. CONSTITUTION: The grid kick circuit for feeding the beam interrupting bias to a grid(G1) of a kinescope(10) to provide the spot burn protection includes a first common emitter switching circuit(Q1) having an output(C1) combined to a first electrode(1) of the grid kick capacitor(CK) and a second common emitter switching circuit(Q2) having an output(C2) combined to a second electrode(2) of the capacitor(CK) and to the grid(G1); independent first and second current channels providing the improve charging efficiency of the capacitor(CK); an active pull-down of the capacitor voltage providing the increased interrupting speed; and the grid bias voltage controlled while normally operating if the voltage is not desired to be interrupted.